OBJECTIVE. Body image and perceived attractiveness were examined, and the impact of age, gender, and body mass index (BMI) was analyzed and discussed from an evolutionary and a sociocultural perspective. METHOD. The population-based sample consisted of 11,468 Finnish men and women aged 18 to 49 years. RESULTS. Both age-related decrease and increase in body satisfaction was detected as well as interactions between age and gender. Some effects were nonlinear. Women were generally less satisfied with their bodies than men. BMI had a stronger influence on women's body image than men's. DISCUSSION. It was proposed that it is insufficient to merely study how age affects general body image because adults might become more satisfied with some aspects of their bodies as a function of age and less satisfied with other aspects. Body satisfaction might also fluctuate during different phases of the adult life, and the patterns possibly differ between men and women.